1. Field of the Invention
The invention relates to a punching bookbinding machine, and more particularly to a combined punching bookbinding machine having capacity of adjusting pass or pitch of holes.
2. Description of the Related Art
Conventional punching bookbinding machines often have less than two kinds of press knife assembly and thereby the punching and binding mode is very limited. Although the punching and binding mode can be modified by disassembling and replacing a knife mould, the storage and maintenance is difficult and a skilled operator required, which results in high cost. Furthermore, different country has different requirement on paper size and punching amount, but the machine cannot achieve the purpose flexibly. Chinese Patent No. 200520015524.4 discloses a punching bookbinding machine having a plurality of press knife and corresponding knife-pressing sheet metal thereof. To reduce the punching amount, a knife-pressing sheet metal is withdrawn, and so the corresponding press knife cannot work. Although the punching bookbinding machine can punch selectively, the pitch of holes and binding mode cannot be adjustable. Currently, there is a punching bookbinding machine having different press knife assembly at each end. However, two kinds of press knife assembly are not yet enough to meet more complicated requirement from clients. Furthermore, upon punching, a working side of the machine must be determined by a specific punching requirement, which is very inconvenient.